8 



present the following formula can be used: Divide the plus reading of the inverted 

 solution at 87 by 163 and multiply by 100. From the polarization at 87 the quantity 

 of levulose in the reducing sugars can be also determined. The reducing sugar 

 present should be nearly equal parts of levulose and dextrose. If a large predomi- 

 nance of dextrose is found and a high content of reducing sugars, with low ash and 

 no iodin reaction, the addition of commercial dextrose is indicated. 



XII. MALIC ACID VALUE. 



This determination is made by a modification of the calcium chlorid 

 method of Leach and Lythgoe 6 and is carried out in the following 

 way : c 



Weigh 6.7 grams of the sample into a 200 cc beaker and add water to make a vol- 

 ume of 20 cc. The solution is made very slightly alkaline with ammonium hydroxid. 

 Add 1 cc of a 10 per cent solution of calcium chlorid and heat to boiling. Then add 

 60 cc of 95 per cent alcohol, cover the beaker with a watch glass, and heat for one- 

 half hour on a water bath. Remove and let stand over night. Filter, through a 9 

 cm No. 589 S. & S. filter, by decantation. Transfer precipitate to the filter by wash- 

 ing with hot 75 per cent alcohol and continue the washing until the entire filtrate 

 measures 100 cc. Dry and ignite. Add from 15 to 20 cc of tenth-normal hydro- 

 chloric acid to the ignited residue, dissolve by careful boiling, cool, and titrate the 

 excess of acid with tenth-normal sodium hydroxid, using methyl orange as indicator. 

 The malic acid value is one-tenth of the number of cubic centimeters of acid neu- 

 tralized by the residue. 



The results obtained do not absolutely express the malic acid 

 present, but give a "value" that is useful in determining whether the 

 product is adulterated. This procedure need only be applied as a 

 confirmatory test of adulteration, as the lead number gives practically 

 the same information. 



Pure maple sugar malic acid value: 



Jones 0.65 to 0.84 ; average, 0.75 



Hortvet._ 0.98 to 1.67; average, 1.29 



Pure maple sirup malic acid value: 



Jones __ 0.41 to 0.72; average, 0.53 



Hortvet 0.84 to 1.76; -average, 1.07 



XIII. PERCENTAGES OF CALCIUM AND POTASSIUM OXID AND SULPHUR 



TRIOXID. 



The complete analysis of the ash of pure maple goods shows it to 

 consist largely of carbonates of lime and potassium, with relatively 

 small amounts of magnesium, sodium, and silica. Sulphates and 

 phosphates are also present in small and varying quantities. The 



U. S. Dept. Agr., Bureau of Chemistry, Bui. 110, p. 17. 

 & J. Amer. Chem. Soc., 1904, 26: 380. 



cj. Amer. Chem. Soc., 1904, 26: 1536; Bureau of Chemistry, Bui. 105, p. 16; Bui. 

 107 Rev., p. 74. 

 [Cir. 40] 





